How do you manage melena (black tarry stools)?

Management of Melena (Black Tarry Stools)

Patients presenting with melena require immediate risk stratification, resuscitation, and endoscopic evaluation to identify and treat the bleeding source, with upper gastrointestinal endoscopy (EGD) as the first-line diagnostic and therapeutic procedure.

Initial Assessment and Stabilization

• Evaluate hemodynamic status immediately, including pulse rate and blood pressure to determine if shock is present (defined as pulse >100 beats/min and systolic BP <100 mmHg) 1
• Begin intravenous fluid resuscitation if hemodynamically unstable, with the goal of normalizing blood pressure and heart rate prior to endoscopic evaluation 1
• Transfuse packed red blood cells to maintain hemoglobin above 7g/dL in most patients; consider a higher threshold of 9g/dL in patients with massive bleeding or significant cardiovascular comorbidities 1
• Correct coagulopathy (INR >1.5) with fresh frozen plasma and vitamin K, and address thrombocytopenia (<50,000/µL) with platelet transfusion 2

Risk Stratification

• Stratify patients into low and high-risk categories for rebleeding and mortality using validated prognostic scales such as Blatchford or Rockall scores 2
• Clinical predictors of increased risk include:
  • Age >65 years, shock, poor overall health status, comorbid illnesses 2
  • Low initial hemoglobin, melena, transfusion requirement 2
  • Fresh red blood on rectal examination, in emesis, or nasogastric aspirate 2
  • Elevated urea, creatinine, or serum aminotransferase levels 2

Diagnostic Approach

• EGD should be the initial procedure of choice as it has both diagnostic and therapeutic capabilities 1
• Perform emergency endoscopy within 24 hours for unstable patients or those with evidence of ongoing bleeding 1
• For hemodynamically stable patients without active bleeding, early elective endoscopy (ideally the morning after admission) is appropriate 1
• Melena strongly predicts bleeding from the upper gastrointestinal tract or proximal small intestine - studies show the presence of melena doubles the odds of finding a bleeding site in the proximal small intestine 3

Endoscopic Management

• During EGD, identify the source of bleeding and apply appropriate endoscopic therapy if active bleeding, non-bleeding visible vessel, or adherent clot is found 1
• Common causes of melena include peptic ulcer disease (most common), gastric erosions, esophagitis, Mallory-Weiss tears, and vascular malformations 1, 4
• Endoscopic treatment options include:
  • Injection therapy with dilute adrenaline, thrombin, or fibrin glue 5
  • Thermal methods such as heater probe, multipolar electrocoagulation, or Argon plasma coagulation 5
  • Mechanical methods like endoclips 5
• Following successful endoscopic therapy in patients with ulcer bleeding, high-dose proton pump inhibitor therapy (80 mg stat followed by infusion of 8 mg hourly for 72 hours) is recommended 1

Further Investigation if EGD is Non-diagnostic

• If initial EGD is non-diagnostic, colonoscopy should be performed to evaluate for potential lower GI sources of bleeding, although the diagnostic yield is relatively low (4.8%) 6
• For patients with continued bleeding and non-diagnostic upper and lower endoscopy, consider:
  • Small bowel capsule endoscopy for stable patients 4
  • CT angiography (CTA) for active bleeding cases, which can detect bleeding rates as low as 0.3 mL/min 2
  • Angiography with potential for therapeutic embolization in cases of active bleeding 2

Special Considerations

• Rare but life-threatening causes of melena such as aortoenteric fistula should be considered in patients with massive bleeding, especially those with a history of aortic aneurysm or previous vascular surgery 7
• Elderly patients (>65 years) have significantly higher mortality rates and require more aggressive management 1
• Patients with significant comorbidities (especially cardiovascular, renal, or liver disease) are at higher risk for complications and mortality 1

Management Algorithm

1. Resuscitate and stabilize the patient
2. Risk stratify using clinical criteria and prognostic scores
3. Perform urgent EGD (within 24 hours)
4. Apply appropriate endoscopic therapy if bleeding source identified
5. Start high-dose PPI therapy after successful endoscopic treatment
6. If EGD is negative, proceed to colonoscopy
7. If both are negative and bleeding persists, consider small bowel evaluation with capsule endoscopy or CTA/angiography